Don't allow CONFIG_PREEMPT with Linux 2.6.x before 2.6.21, because it's busted.

diff --git a/datapath/linux-2.6/compat-2.6/compat26.h b/datapath/linux-2.6/compat-2.6/compat26.h
index 80132324666ea84947e23e8d144f2ba04dbca803..04335f7da2699c343b761697b8026144d5d3e159 100644 (file)
--- a/datapath/linux-2.6/compat-2.6/compat26.h
+++ b/datapath/linux-2.6/compat-2.6/compat26.h
@@ -3,6 +3,10 @@
 
 #include <linux/version.h>
 
+#if defined(CONFIG_PREEMPT) && LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,21)
+#error "CONFIG_PREEMPT is broken with 2.6.x before 2.6.21--see commit 4498121ca3, \"[NET]: Handle disabled preemption in gfp_any()\""
+#endif
+
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
 /*----------------------------------------------------------------------------
  * In 2.6.24, a namespace argument became required for dev_get_by_name. */